It began with a hip check that took out Boston Celtics guard Shane Larkin in the closing seconds of the first quarter, a pick by Joel Embiid that was delivered with such precision that the reserve guard immediately left the court and never returned.

It continued just minutes later as Embiid and Celtics point guard Terry Rozier got tangled up while fighting for the basketball, leading to what looked like a punch thrown at the Sixers center.

And it reached a crescendo late in the third quarter when Embiid got tangled up with Boston’s Marcus Morris, an exchange that ended with the Celtics forward holding up three fingers to let everyone know the number of wins the Celtics had in the series going into Monday.

Playing at a grind-it-out pace is not Philadelphia’s style: Coach Brett Brown prefers the fast, frenetic pace that often ends with his team jacking up quick 3-pointers. But Embiid laid the wood on the Celtics in the 103-92 win by the Sixers on Monday, and in doing so he saved Philadelphia from an embarrassing second-round sweep.

Embiid didn’t shoot the ball well: He scored 15 points (6-of-15 from the field). But he grabbed 15 rebounds and, despite not having any blocks, was active and physical on both ends.

“They were physical, they were tough,” said Boston coach Brad Stevens. “We lost our poise, and that had a lot to do with Philadelphia. They pounded on us.”

Embiid’s hard pick on Larkin knocked the Celtics backup guard out with a left shoulder injury. He never returned to the lineup and will be evaluated Tuesday.

The scuffle with Rozier came two minutes into the second quarter when Embiid tried to get the ball from the Celtics guard after a Boston turnover. Rozier stepped to Embiid and appeared to throw two punches at the Sixers center. But after an official review, neither player was thrown out, and both Embiid and Rozier received technical fouls.

“He tried to punch me in my face,” Embiid said. “Too bad he’s so short that he couldn’t get to my face. I didn’t understand why it was a double technical, because I was just trying to get the ball. He was the one trying to swing.”

Later in the third quarter, Embiid challenged a Morris layup and may have gotten a little body after the Celtics forward fell to the ground on the miss. Embiid gave a glare at Morris that would have made ex-Sixers center Dikembe Mutombo, who was sitting courtside, proud.

The two players kept jawing over the next couple of minutes and into a timeout. That’s when Morris flashed three fingers, the sign of how many games the Celtics were up in the series.

Sixers point guard Ben Simmons explained it this way: “Jo’s a beast. For someone to frustrate him and get under his skin, I just think the result is that he’s going to go harder.”

On a night where Dario Saric led the Sixers in scoring with 25 points and T.J. McConnell scored a career-high 19 points in replacing Robert Covington in the starting lineup, Embiid’s physical contributions established the physical nature of Monday’s win.

That physical play knocked the Celtics off their rhythm. Morris, Jaylen Brown and Marcus Smart each had five fouls for the Celtics, and Jayson Tatum, who led the team with 20 points, picked up three fouls by halftime (including two quick fouls in the opening minutes).

The Sixers made an effort early to get inside, and that showed in the team’s dominance in points in the paint (a 52-30 advantage for Philadelphia).

Still, the team’s reliance on the 3-point shot made fans nervous. With a 10-point lead late in the fourth quarter, both J.J. Redick and Embiid launched early 3s, the kind of quick offense that allowed Boston to come back from a 22-point deficit in the game and overcome a comedy of Sixers errors in the overtime win in Game 3.

“How are we going to score?” Brown said after the game. “Joel at times ends up being the obvious answer, but we go inside to generate 3s.”

That’s a philosophy that might ultimately doom the Sixers. The fact that they live to see another day will be credited to McConnell’s career night in sparking the offense.

But before the Sixers guard got untracked, Embiid set the tone. Embiid showed up at the postgame news conference wearing what appeared to be a simple white T-shirt.

Only when he got up to leave was the message Embiid wanted to deliver revealed: